Differential turbine for fluid transmission



March 11, l947- A. J. WEATHERHEAD, .1R j 2,417,224

DIFFERENTIAL TURBINE FOR FLUID` TRANSMISSION Filed Jan. 6. 1944 2SheetsSheet 1 III. l

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DIFFERENTIAL TURBIN=E FOR FLUID TRANSMISSION Filed Jan. 6 1944 2Sheets-Sheet 2 Iig 3 A L BEPT J WFA THIEHEAD, 7E

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Patented Mar. 11, 1947 DIFFERENTIAL TURBINE FOR FLUID TRANSMISSIONAlbert J. Weatherhead, Jr., Shaker Heights, Ohio,

assignor to The Weatherhead Company, Cleveland, Ohio, a corporation ofOhio Application January 6, 1944, Serial No. 517,163

This invention relates to a fluid power transmission, and morespecifically to a differential fluid turbine.

The principal object of this invention is to drive two shafts, or drivenmembers, through a fluid turbine, so that the relative speed of theshafts may vary in accordance with variations ln the loadsimposedthereon.

A further object is to combine two driven shafts with a hydraulicturbine to drive the shafts, so that the single unit may replace adriving gear and a differential gear set.

Other objects are totransmit power from a prime mover to a pair ofcoaxial shafts through a fluid turbine serving as a differential, and to-drive the turbine in either direction with uid from the prime mover soas to permit reversing the direction of rotation of the driven shaft.

Other objects relating to detalls of construction and economies ofmanufacture will appear hereinafter.

In the accompanying drawings:

Fig. 1 is a section through a turbine embodying this invention, takensubstantially on the line l-I of Fig. 2;

Fig. 2 ls a section taken on the line 2--2 of Fig. 1;

Fig. 3 is a section through a modified form embodying a reverse drive,the section being taken substantially on the line 3-3 of Fig. 4;

Fig. 4 is a section taken on the line 4-4 of Fig. 3; and

Fig. 5 is a diagrammatic view of a driving member arranged to drive thedriven shafts through a coupling embodying the invention.

Referring to Figs. l and 2 of the drawings, the turbine is enclosed ina, generally cylindrical casing 5. The side walls of the casing 5 areformed with aligned openings E into which are fitted flanges 'I carriedby bearing caps 8. The casing 5 is preferably formed with inwardlyextending cylindrical flanges 9 tting against the outer surface of theflanges 1. Aligned driven shafts I and II are supported in the oppositebearing caps As shown, each flange 1 carries a ball race I2, andcooperating ball races I3 are carried by the shafts I0 and II, with ballbearings I4 operatively disposed between the two races, A fluid seal Iof any suitable type is vmounted in each bearing cap 8 and held inposition by a nut I6. The shafts I0 and II extend freely through centralapertures in the nuts I 6.

The inner ends pf the shafts I0 and I i are provided with rotorscarrying turbine blades of any 1 Claim. (Cl. 253-25) desired type, thetwo sets of blades being disconnected from each other but positionedclosely adjacent each other. In the'embodiment illustrated the shafts i0and II are provided with spaced discs I1 and I8 of a diameter to fitclosely within the major portion of the inner circumference of thecasing 5. A plurality of blades 2| are mounted on the disc I1 on theshaft I Il, and a similar set of blades 22 are mounted on the disc I8 onthe shaft II. The ends of the shafts I0 and II may be extended to engageeach other as indicated at 23 to maintain a narrow spacing between theblades 2i and 22. Any other suitable form of thrust bearing may, ifdesired, tween the shafts I0 and II.

A fitting 24 is secured to the top of the casing ln any suitable manner,as by the bolts 25, and supports an inlet nozzle-26 directedtangentiallyy to the blades 2i and 22. The nozzle 26 is provided with aninlet bore 21, a. Venturi restriction 28, and a flared nozzle opening29. A fluid pressure supply line is connected to the nozzle 2G in-anysuitable manner as by a fitting 30 screwed Vinto the outer surface ofthe fitting 24, both fittings being provided with bores axially alignedwith the inlet bore 21 of the nozzle 26.

The nozzle 26 is directed tangentlally against the blades 2i and 22 andis located centrally with respect to the two sets of blades 2i and 22 sothat the fluid stream ejected by the nozzle 26 is divided equallybetween the two sets of blades 2i and 22. The blades`2| and 22 arecupped in the axial direction, as illustrated, so that the adjacentedges of the two sets of blades split the fluid stream from the nozzle26 and each blade directs its part of the stream arcuately across theblade so that the energy of the fluid is transmitted to the shafts withas little loss as possible.

In the radial direction the blades 2| and 22 may be substantiallystraight as illustrated in Fig. 2 and are preferably set at an angle tothe radii of the discs i1 and I8 so as to be presented substantiallyperpendicular to the stream of fluid entering, through the nozzleg26.

An outlet is formed in the casing, preferably at a point about 270 fromthe point where the stream from the inlet nozzle 26 strikes the blades2i and 22. As illustrated, the casing 5 is formed with a shoulder 3|providing a generally triangular pocket 32 between the casing and thecircle defined by the outer edges of the blades 2| and 22. A pipefitting 33 may be screwed through the be provided be.

the inlet nozzle 28 on the opposite .side of the rotors.

With this arrangement fluid under pressure pumped into the inlet nozzle26 through the supply pipe is delivered through the flared opening 29 ata high velocity by reason o f the Venturi restriction 20. The enteringstream of fluid initially strikes the blades 2| and 22 and impartsenergy to the two shafts i and by the impact of the fluid against theblades. Normally the forward momentum ofthe fluid is not completelyabsorbed Vby the impactof the fluid against the blades and .the fluidcontinues to impart energy to the shafts |0 and i| as it is carriedaround between adjacent blades and within the casing 5. As the shaftsrotate the fluid trapped between each pair of adjacent blades enters thespace 32 and is forcibly directed toward the outlet bore through thefitting 33. Thus in operation a layer of fluid is normally presentadjacent 'the outer edges of the blades 2| and 22 and is retainedtherein by the casing wall and discharged t rough the discharge letting33 so that the blades are substantially free of fluid when they areagain presented to the inlet nozzle 26.

Normally the two shafts ill and il are driven at the same speed ofrotation with a given pressure and velocity of the fluid enteringthrough the inlet nozzle 25, assuming hat the load or resistance on thetwo shafts is equal. Any variation ofthe load on the one shalt withrespect to the load on the other permits one shaft with its set ofblades 2| or 22 to rotate more rapidly than the other shaft. Suchvariation in the speed of rotation of the two shafts does not affect thequantity of fluid initially delivered to the two sets of blades so thatthe total torque on the two shafts remains substantially constant.

In Figs. 3 and 4 I have illustrated a modification in which the discsi|1 arid ||8 carry on their outer surfaces turbine blades or buckets |35and |36 respectively. On opposite sides of the outlet |33 the casing |05is provided with a pair of inlet nozzles |31 'and |38 positioned todirect streams of fluid against the blades |35 and |36 so as to rotatethe two shafts ||0 and iii in the opposite direction from that in whichthey are driven by the single inlet |24. Outlet fittings |39 arearranged on opposite sides of the main inlet fitting |24 to dischargethe fluid entering through the nozzles |31 and |38 when the shafts arebeing driven in reverse. Each of the inlet nozzles |31 and i 38 isprovided with a Venturi restriction |40 in the same manner as the inletnozzle 26 previously described. The fluid supply to the main nozzle |30may be cut off and the fluid supply to the nozzles |31 andI3|lsimultaneously opened so that the streams of fluid from the nozzles|31 and |38 serve to bring the'shafts ||0 and iii to rest and then drivethem in the reverse direction.-

Since the fluid delivered by the nozzles |31 and |38 is free to passaxially within the casing it may enter the spaces between the blades |2|and |22 and thus serve to exert a force tending to maintain the speed ofthe shafts i|0 and the same d when the shafts are being driven inreverse.

I have shown diagrammatically in Fig. 5 an arrangement in which the twoshafts ||0 and are driven differentially by a single driving member. Thedrive shaft |42 is arranged to be rotated'by any suitable prime mover.and is con' nected to a fluid pump |43 of any desired type. A pipe |44,leads the fluid under pressure delivered by the pump to a three-wayvalve |45. When the handle |46 of the valve |45 is in the full lineposition, fluid under pressure is directed into the pipe |41 leading tothe inlet fitting |30 in the turbine casing |05. When the handleof thevalve |45 is moved to the dotted line position, the pressure fluid isdirected into the pipe |40 leading to the two inlet nozzles |31 and |33.The outlet f1ttings |33 and |39 are in constant communication with thepipe |49 connected to the low pressure side of the pump |43 as to returnthe fluid to the pump regardless of the position of the valve.

Although preferred embodiments of the invention have been described inconsiderable detail, it will be understood that many variations andmodifications may be resorted to without departing from the scope of theinvention as defined in the following claim.

I claim:

A differential turbine comprising a casing. a pair of aligned shaftsjournalled in said casing, a set of turbine blades arrangedcircumferentially about each of said shafts and positioned closelyadjacent each other, said blades being cupped and having their concavesides facing in the same direction, a second set of blades carried byeach of said shafts. said second setsof blades being cupped and having.their concave sides facing in the opposite direction to the firstmentioned set of blades, an inlet nozzle formed in said casing arrangedto direct a stream of fluid under pressure at the adiacent side edges ofthe concave faces of said first mentioned set of blades. an outt openingin said casing spaced circumferentialn ly from said inlet nozzle. spacedauxiliary nozzles aligned with said outlet opening and arranged todirect fluid against said second sets of blades and auxiliary outletopenings for said second sets of blades aligned with said inlet nozzle.

ALBERT J. WEATHERHEAD, Jn.

.REFERENCES CITED The following references are -of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 2,194,316 Messlnger Mar. 19, 19402,024,663 Schrag Dec. 17, 1935 578,759 McElroy Mar. 16, 1897 600,007Langer Mar. 1, 189B 865,160 Clark Sept. 3, 1907 752,545 De Goede Feb.16, 1904 FOREIGN PATENTS Number Country Y Date 382,963 Galvin (French)1908 8,975 Dureigne (British) 1913 4,638 Enoek (British) 1899

